JP2022038399A - Surface-emitting light source and manufacturing method for the same - Google Patents

Abstract

To provide a surface-emitting light source capable of efficiently diffusing light from a light-emitting element and a manufacturing method for the same.SOLUTION: A surface-emitting light source 100 includes a wiring substrate 15, a light guide plate 6, a light-reflecting member 7A, a light-emitting element 2, and a light-diffusing layer 4 installed on a light-extracting side of the light-emitting element 2. The light-diffusing layer 4 contains glass beads. The glass beads are one or more of hollow glass beads, glass beads containing TiO2, glass beads containing Ag, and glass beads containing Al.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to a surface emitting light source and a method for manufacturing the same.

A light emitting device using a light emitting element such as a light emitting diode is widely used as a surface light source such as a backlight of a liquid crystal display as an example. For example, in Patent Document 1, a housing having a first light medium having a first light scattering ability and a second light medium having a second light scattering ability is arranged in the housing. A light emitter having a plurality of light sources is disclosed.

Special Table 2007-524206 Gazette

It is an object of the present embodiment to provide a surface light emitting light source capable of efficiently diffusing the light of a light emitting element and a method for manufacturing the same.

The surface light emitting light source according to the embodiment of the present disclosure is installed between a wiring board having a wiring layer on a base material, a light guide plate installed facing the wiring board, and the light guide plate and the wiring board. A light emitting element installed on the wiring board facing the light guide plate on the light extraction surface side and installed on the light extraction surface side of the light emitting element through the light reflecting member and the opening of the light reflecting member. The light diffusing layer comprises a glass bead, and the glass bead contains a hollow glass bead, a glass bead containing TiO ₂ , a glass bead containing Ag, and Al. One or more of the glass beads to be used.

The surface light emitting light source according to the embodiment of the present disclosure is installed between a wiring board having a wiring layer on a base material, a light guide plate installed facing the wiring board, and the light guide plate and the wiring board. The light emitting surface side is provided to the light guide plate via the light transmitting member, the reflective film installed at the position on the lower surface side of the light guide plate facing the upper surface of the light transmitting member, and the opening of the light transmitting member. A light emitting element installed on the wiring substrate facing each other and a light diffusing layer installed on the light extraction surface side of the light emitting element are provided, the light diffusing layer contains glass beads, and the glass beads are , Hollow glass beads, glass beads containing TiO ₂ , glass beads containing Ag, and one or more of glass beads containing Al.

In the method for manufacturing a surface light emitting light source according to the embodiment of the present disclosure, a light guide plate is prepared and a light emitting layer is provided on the light extraction surface side through an opening of a light reflecting member installed on a base material. A preparatory step in which the element prepares an intermediate body installed on the base material with the surface opposite to the light extraction surface facing the base material, and the light extraction surface of the light emitting element facing the light guide plate. The light diffusion layer contains glass beads and includes the glass beads, including an bonding step of adhering the light source plate to the intermediate in a state of being brought into the state, and a wiring layer forming step of forming a wiring layer on the base material. Is one or more of hollow glass beads, glass beads containing TiO ₂ , glass beads containing Ag, and glass beads containing Al.

In the method for manufacturing a surface emitting light source according to the embodiment of the present disclosure, the light guide plate having a reflective film installed at a position on the lower surface side of the light guide plate facing the upper surface of the light transmitting member is prepared and installed on a base material. A light emitting element having a light diffusion layer installed on the light extraction surface side is installed on the base material with the surface opposite to the light extraction surface facing the base material through the opening of the light transmission member. A preparatory step for preparing the intermediate body, a bonding step for adhering the light guide plate to the intermediate with the light extraction surface of the light emitting element facing the light guide plate, and forming a wiring layer on the base material. The light diffusion layer contains glass beads, and the glass beads contain hollow glass beads, glass beads containing TiO ₂ , glass beads containing Ag, and Al. One or more of the glass beads to be used.

The surface light emitting light source according to the embodiment of the present disclosure is a wiring substrate having a wiring layer on a base material, a light guide plate, and a first member which is partially opened and installed between the light guide plate and the wiring board. The first member comprises a light emitting element installed on the wiring substrate and a light diffusing layer installed between the light emitting element and the light guide plate through the opening of the first member. The member is a light reflecting member or a light transmitting member, and the light diffusing layer contains glass beads and does not overlap with a region where the light guide plate and the light diffusing layer overlap when transmitted in a plan view. In a plan view, the area of the light diffusing layer is the same as the area of the light emitting element or larger than the area of the light emitting element.

According to the embodiment according to the present disclosure, it is possible to provide a surface light emitting light source capable of efficiently diffusing the light of a light emitting element and a method for manufacturing the same.

It is a perspective view which shows schematically the whole from the surface side by omitting a part of the surface light emitting light source which concerns on embodiment. It is a perspective view schematically showing a part of the surface light emitting light source which concerns on embodiment enlarged from the back surface side. It is sectional drawing which shows typically the cross section in the line III-III of FIG. It is a top view which shows typically the light emitting structure of the surface light emitting light source which concerns on embodiment. It is sectional drawing which shows typically the light source of the surface light emitting light source which concerns on embodiment. It is sectional drawing which shows typically the hollow glass beads contained in the light diffusion layer of the surface light emitting light source which concerns on embodiment. It is sectional drawing which shows typically the glass bead containing TIO ₂ contained in the light diffusion layer of the surface light emitting light source which concerns on embodiment. It is sectional drawing which shows typically the glass beads containing Ag contained in the light diffusion layer of the surface light emitting light source which concerns on embodiment. It is sectional drawing which shows typically the glass beads containing Al contained in the light diffusion layer of the surface light emitting light source which concerns on embodiment. It is sectional drawing which shows typically the light source of the surface light emitting light source which concerns on embodiment. It is sectional drawing which shows typically the light source of the surface light emitting light source which concerns on embodiment. It is a flowchart which shows the manufacturing method of the surface light emitting light source which concerns on embodiment. It is sectional drawing which shows typically the light guide plate prepared in the preparation process of the manufacturing method of the surface light emitting light source which concerns on embodiment. It is sectional drawing which shows typically the intermediate prepared in the preparation process of the manufacturing method of the surface light emitting light source which concerns on embodiment. It is sectional drawing which shows typically the state which the light guide plate and the intermediate are bonded in the bonding process of the manufacturing method of the surface light emitting light source which concerns on embodiment. It is sectional drawing which shows typically the state which formed the wiring layer in the wiring layer formation process of the manufacturing method of the surface light emitting light source which concerns on embodiment. It is sectional drawing which shows typically the surface light emitting light source which concerns on the modification. It is sectional drawing which shows typically the surface light emitting light source which concerns on the modification. It is sectional drawing which shows typically the surface light emitting light source which concerns on the modification. It is sectional drawing which shows typically the surface light emitting light source which concerns on the modification.

Since the drawings referred to in the description according to the following embodiments schematically show the present invention, the scale, spacing, positional relationship, etc. of each member are exaggerated, or a part of the members is not shown. May be. In addition, the scales and spacing of each member may not match. Further, in the following description, the same or the same quality members are shown in principle for the same name and reference numeral, and detailed description thereof will be omitted as appropriate. Further, in the configuration of the surface light emitting light source, "upper", "lower", "left", "right" and the like are interchanged depending on the situation. In the present specification, "top", "bottom", etc. indicate relative positions between components in the drawings referred to for explanation, and indicate absolute positions unless otherwise specified. Not intended. Further, for example, "installation" means a case of installing directly on a member, a case of installing via another member, a case of being arranged between predetermined members, and the like.

<Surface light source>
The surface emitting light source 100 will be described with reference to FIGS. 1 to 6B.
FIG. 1 is a perspective view schematically showing the entire surface emitting light source according to the embodiment from the surface side, omitting a part of the surface emitting light source. FIG. 2 is a perspective view schematically showing a part of the surface emitting light source according to the embodiment enlarged from the back surface side. FIG. 3 is a cross-sectional view schematically showing a cross section taken along the line III-III of FIG.
FIG. 4A is a plan view schematically showing a light emitting structure of a surface light emitting light source according to an embodiment.
FIG. 4B is a cross-sectional view schematically showing a light source of the surface emitting light source according to the embodiment.

FIG. 5A is a cross-sectional view schematically showing hollow glass beads contained in the light diffusion layer of the surface light emitting light source according to the embodiment. FIG. 5B is a cross-sectional view schematically showing glass beads containing TIO ₂ contained in the light diffusion layer of the surface light emitting light source according to the embodiment. FIG. 5C is a cross-sectional view schematically showing a glass bead containing Ag contained in the light diffusion layer of the surface light emitting light source according to the embodiment. FIG. 5D is a cross-sectional view schematically showing Al-containing glass beads contained in the light diffusion layer of the surface light emitting light source according to the embodiment.

FIG. 6A is a cross-sectional view schematically showing a light source of the surface emitting light source according to the embodiment. FIG. 6B is a cross-sectional view schematically showing a light source of the surface emitting light source according to the embodiment.
6A and 6B are drawings for explaining the relationship between the light diffusing layer and the glass beads when the light diffusing layer is made into two layers.

The surface light emitting light source 100 is light installed between the wiring board 15 having the wiring layer 17 on the base material 16, the light guide plate 6 installed facing the wiring board 15, and the light guide plate 6 and the wiring board 15. The light emitting element 2 installed on the wiring board 15 facing the light guide plate 6 on the light extraction surface side through the reflection member 7A and the opening of the light reflection member 7A, and installed on the light extraction surface side of the light emitting element 2. The light diffusing layer 4 is provided. The light diffusion layer 4 contains glass beads 60. The glass beads 60 are preferably one or more of the hollow glass beads 61, the glass beads 62 containing TiO ₂ , the glass beads 63 containing Ag, and the glass beads 64 containing Al. This makes it possible to provide a surface light emitting light source 100 capable of efficiently diffusing the light of the light emitting element 2. The wiring layer 17 refers to the first wiring layer 17A and / or the second wiring layer 17B.

Alternatively, the wiring board 15 having the wiring layer 17 on the base material 16, the light guide plate 6, the first member 7 which is partially opened and installed between the light guide plate 6 and the wiring board 15, and the first member. A light emitting element 2 installed on the wiring board 15 and a light diffusion layer 4 installed between the light emitting element 2 and the light guide plate 6 are provided through the opening of 7. The first member 7 is a light reflecting member 7A or a light transmitting member 7B, and the light diffusing layer 4 contains glass beads 60. Further, there is a region where the light guide plate 6 and the light diffusing layer 4 overlap and a region where the light diffusing layer 4 does not overlap when transmitted in a plan view. In a plan view, the area of the light diffusing layer 4 is the same as the area of the light emitting element 2 or larger than the area of the light emitting element 2. This makes it possible to provide a surface light emitting light source 100 capable of efficiently diffusing the light of the light emitting element 2. The first member 7 is a light reflecting member 7A or a light transmitting member 7B, and although the light reflecting member 7A will be described as an example in FIG. 3 and the like, the light transmitting member 7B may also be used.
Hereinafter, each configuration of the surface emitting light source 100 will be described.

In the surface light emitting light source 100, a plurality of light emitting modules 10 can be arranged on a wiring substrate 15 via an adhesive sheet 20 by arranging them in a rectangle of, for example, 2 columns or more and 200 columns or less × 2 rows or more and 200 rows or less. The light emitting module 10 is configured by arranging a plurality of light emitting structures 1 in a rectangle having, for example, 2 columns or more and 200 columns or less × 2 rows or more and 200 rows or less.

[Wiring board]
The wiring board 15 aligns a plurality of light emitting modules 10 via the adhesive sheet 20 and supplies a current to the light emitting modules 10 from the outside. Further, the wiring board 15 has a first wiring layer 17A formed on one side of the base material 16 and the base material 16, and an adhesive sheet 20 on the other side opposite to the one side on which the first wiring layer 17A is formed. A second wiring layer 17B formed through the wiring layer 17B is provided. The wiring board 15 includes a pair of wiring pads 18 continuous with the first wiring layer 17A formed on the base material 16 for each light emitting module 10. At least two (four in FIG. 2) via holes 18a1 and 18a2 are formed in the pair of wiring pads 18, respectively. It is preferable that the pair of wiring pads 18 are provided on one side of the wiring board 15. Further, here, the wiring board 15 is provided with a covering layer 19 so as to form an opening for exposing the wiring pad 18 on one surface side, and a second wiring layer 17B is provided on the other surface side via the adhesive sheet 20. , A plurality of light emitting modules 10 are arranged on the second wiring layer 17B.

The base material 16 forming the wiring substrate 15 has an insulating property, and is, for example, a phenol resin, an epoxy resin, a polyimide resin, a polyethylene terephthalate, a polyethylene naphthalate, a silicone resin, a bismaleimide triazine resin (BT resin), a polyphthalamide, or the like. It is made of an insulating resin material. Further, the base material 16 may have an insulating member formed in a layer on the surface of the metal member. Further, as the wiring board 15, a rigid board or a flexible board can be used. Further, the wiring board 15 may be a stack of a plurality of base materials 16.
Metallic materials can be used for the first wiring layer 17A, the second wiring layer 17B, and the wiring pad 18, which are the wiring layers 17, for example, Ag, Al, Ni, Rh, Au, Cu, Ti, Pt, Pd, and so on. Elemental metals such as Mo, Cr and W or alloys containing these metals can be preferably used. More preferably, a simple substance metal such as Ag, Al, Pt, Rh or the like having excellent light reflectivity or an alloy containing these metals can be used.
The coating layer 19 can be formed by using a polyimide resin, a phenylsilicone resin, a dimethylsilicone resin, or the like.
As the adhesive sheet 20, a thermosetting resin such as urethane resin can be used.

The surface light emitting light source 100 preferably includes a conductive member 30 filled across the two via holes 18a1 and a protective member 40 provided so as to cover the conductive member 30 from one side of the wiring board 15. As the conductive member 30, for example, a mixture of a flake-shaped, scaly or bark-shaped filler such as silver powder or copper powder and a thermosetting binder resin can be used. As the protective member 40, the same material as that of the coating layer 19 can be used.

[Light emitting structure]
The light emitting structure 1 preferably includes, for example, a light source 11, a light guide plate 6, and a light reflecting member 7A. The light source 11 is provided on the light emitting element 2, the translucent member 3 provided on the light extraction surface of the light emitting element 2, the light diffusion layer 4 provided on the upper surface of the translucent member 3, and the side surface of the light emitting element 2. It has a covering member 5. The upper surface of the translucent member 3 is a surface installed facing the light guide plate 6. The light reflecting member 7A is provided on the side surface of the covering member 5, and the light guide plate 6 is provided on the light reflecting member 7A and the light diffusion layer 4.

As the light emitting element 2, for example, a known semiconductor light emitting element can be used, and a light emitting diode is exemplified as the light emitting element 2. The light emitting element 2 may use a light source that emits blue light, or may use a light emitting element that emits a plurality of different colored lights, and can, for example, mix red, blue, and green colored lights to emit white light. .. As the light emitting element 2, an element that emits light of an arbitrary wavelength can be selected, and the composition, emission color, size, number, etc. of the light emitting element to be used can be appropriately selected according to the purpose. .. For example, as an element that emits blue or green light, a nitride-based semiconductor (In _x Aly Ga _{1-xy N} , 0 ≦ X, 0 ≦ Y, X + Y ≦ 1) or a light emitting device using GaP is used. Can be used. Further, as the element that emits red light, a light emitting element containing a semiconductor such as GaAlAs or AlInGaP can be used. Further, a semiconductor light emitting device made of a material other than the above can also be used, and various emission wavelengths can be selected depending on the material of the semiconductor layer and the crystal mixture degree thereof.

The translucent member 3 is a member that adjusts the emission color of the light emitting element 2. The translucent member 3 contains a translucent material and a phosphor that converts the wavelength of light. As the translucent material, a material having a higher refractive index than the material of the light guide plate 6 is preferable. Epoxy resin, silicone resin, modified epoxy resin, modified silicone resin or a resin mixed thereof, glass or the like can be used, but from the viewpoint of light resistance and moldability, silicone resin or modified epoxy resin is selected. It is preferable to do so.

The translucent member 3 has a different range of convertible wavelengths depending on the type of phosphor, and it is necessary to select an appropriate phosphor in order to obtain a desired wavelength for conversion. As the phosphor, for example, a fluoride-based phosphor such as a YAG phosphor, a LAG phosphor, a chlorosilicate-based phosphor, a β-sialon phosphor, a CASN phosphor, a SCASSN phosphor, or a KSF-based phosphor can be used. .. In particular, it is preferable to use a plurality of types of phosphors in one translucent member 3, and more preferably, the light emitting element 2 having a light emission peak in the near-ultraviolet to blue region and the translucent member 3 emit green light. By including the β-sialon phosphor and the fluoride-based phosphor such as the KSF-based phosphor that emits red light, the color reproduction range of the surface light emitting light source 100 can be expanded.

Further, the translucent member 3 can emit light of a specific color by containing a phosphor that emits light of a specific color. Further, the translucent member 3 can also contain quantum dots. There is no limitation on the arrangement mode of the fluorescent materials in the translucent member 3, and the fluorescent materials may be distributed substantially uniformly, unevenly distributed in a part thereof, or a plurality of layers containing different fluorescent materials may be laminated. , It is possible to select an effective embodiment.

The light diffusing layer 4 is a member that diffuses the light from the light emitting element 2, and here, is a member that diffuses the light transmitted through the translucent member 3. The light diffusion layer 4 contains glass beads 60. The light diffusion layer 4 uses the above-mentioned translucent material as a base material, and glass beads 60 are added to the base material in a dispersed state. In a plan view, the area of the light diffusing layer 4 is preferably the same as the area of the light emitting element 2 or larger than the area of the light emitting element 2. When the area of the light diffusing layer 4 is larger than the area of the light emitting element 2, the area of the light diffusing layer 4 is preferably the same as the area of the translucent member 3 provided in the light emitting element 2.

Examples of the glass beads 60 include hollow glass beads 61, glass beads 62 containing TiO ₂ , glass beads 63 containing Ag, and glass beads 64 containing Al. When the light diffusing layer 4 contains the glass beads 62 containing TiO ₂ , the light diffusing action between the light diffusing layer 4 and the glass beads 60 can be improved. That is, the refractive index of the light diffusing layer 4 is improved by containing TiO ₂ having a high refractive index, and the light diffusing action is improved by increasing the difference in refractive index between the translucent member 3 and the light diffusing layer 4. Can be done. Further, when the light diffusing layer 4 contains the glass beads 63 containing Ag and the glass beads 64 containing Al, the light diffusing action of the light diffusing layer 4 can be improved. That is, by containing Ag or Al having a high light reflectance in the visible light region, the reflectance of the light diffusing layer 4 can be improved, and the light diffusing action of the light diffusing layer 4 can be improved.

The light diffusion layer 4 may contain one of these glass beads, or may contain two or more of these glass beads. The light diffusion layer 4 more preferably contains two or more of these glass beads. When the light diffusion layer 4 contains two or more of these glass beads, the refraction and reflection of light are diversified by the glass beads having different refractive indexes and reflectances, and the refractive index and reflectance are increased, so that the light is light. The diffusion effect is improved.
The material of the outer shell of the glass beads 60 is soda-lime glass, silicic acid-based glass, borosilicate glass, alkaline borosilicate glass, aluminosilicate glass and the like. Further, the refractive index of the glass beads 60 is preferably 1.8 or more from the viewpoint of light diffusivity. Lead oxide, vanadium oxide, phosphorus oxide, molybdenum oxide and the like can be added to the glass beads 60 in order to improve the refractive index, strength and sphericity.

The hollow glass beads 61 are, for example, fine glass spheres containing an air layer 51 inside the outer shell 50 of the glass.
The glass beads 62 containing TiO ₂ are, for example, fine glass spheres containing an air layer 51 inside the outer shell 50 of glass, in which aggregates of TiO ₂ 52 are present in the air layer 51. be.
The glass beads 63 containing Ag are, for example, fine glass spheres containing an air layer 51 inside the outer shell 50 of glass, in which aggregates of Ag 53 are present in the air layer 51.
The Al-containing glass beads 64 are, for example, fine glass spheres containing an air layer 51 inside the outer shell 50 of glass, in which aggregates of Al 54 are present in the air layer 51.
In the glass beads 60, the particles such as TiO ₂ are aggregated, so that the particles such as TiO ₂ are easily dispersed in the light diffusing layer 4, and the light diffusing property is improved.

The size of the glass beads 60 is preferably 20 μm or more and 80 μm or less in diameter. When the diameter of the glass beads 60 is 20 μm or more, the light from the light emitting element 2 easily hits the glass beads 60, and the light diffusion efficiency of the light diffusion layer 4 is further improved. From the viewpoint of improving the light diffusion efficiency, it is more preferably 40 μm or more. On the other hand, if it is 80 μm or less, the number of glass beads 60 in the light diffusing layer 4 can be increased without significantly blocking the light from the light emitting element 2, and the light diffusing efficiency of the light diffusing layer 4 is further improved. do. From the viewpoint of improving the light diffusion efficiency, it is more preferably 45 μm or less.

The thickness of the outer shell 50 of the glass is preferably 0.1 μm or more, preferably 0.3 μm or more and 10 μm or less. When the thickness is 0.3 μm or more, the strength of the glass beads 60 is improved. From the viewpoint of improving the strength, it is more preferably 1 μm or more, still more preferably 2 μm or more. On the other hand, if the thickness is 10 μm or less, the weight of the hollow glass beads 61 can be reduced, and the weight of the glass beads 62 containing TiO ₂ can be increased because the amount of aggregates of TiO ₂ 52 can be increased. The light diffusion efficiency of 4 is further improved. It is more preferably 5 μm or less from the viewpoint of reducing the weight or improving the light diffusion efficiency.

The shape of the glass beads 60 is not only a sphere, but also an elliptical body, a regular tetrahedron, a regular hexahedron, a regular octahedron, a regular dodecahedron, a regular polyhedron, and other polyhedra. You may.

As the glass beads 60, glass beads 62 containing TiO ₂ are used from the viewpoint of improving the refractive index, glass beads 63 containing Ag and glass beads 64 containing Al are used from the viewpoint of improving the reflectance, but light diffusion is used. The glass beads 62 containing TiO ₂ are more preferable from the viewpoint of particularly improving the efficiency.
The content of the glass beads 60 is preferably 10% by volume or more and 50% by volume or less with respect to the total volume of the light diffusion layer 4. When the content of the glass beads 60 is 10% by volume or more, the light diffusing action of the light diffusing layer 4 is further improved. From the viewpoint of improving the light diffusion effect, it is more preferably 20% by volume or more. On the other hand, when it is 50% by volume or less, the glass beads 60 are easily dispersed in the light diffusing layer 4, and the light diffusing action of the light diffusing layer 4 is further improved. From the viewpoint of improving the light diffusing action, it is more preferably 30% by volume or less.

In the glass beads 62 containing TiO ₂ , the content of TiO ₂ in one glass bead is preferably 5% by volume or more and 20% by volume or less with respect to the total volume of one glass bead. When the content of TiO ₂ is 5% by volume or more, the refractive index of the light diffusing layer 4 becomes higher and the light diffusing action is improved. From the viewpoint of improving the refractive index, it is more preferably 10% by volume or more. On the other hand, if it is 20% by volume or less, TiO ₂ can be reduced, which is economical. From the viewpoint of economy, it is more preferably 15% by volume or less.

In the glass beads 63 containing Ag, the reflectance becomes high and the light diffusion action is improved. Therefore, the content of Ag in one glass bead is 5% by volume or more and 30 volumes with respect to the total volume of one glass bead. % Or less is preferable. More preferably, it is 10% by volume or more and 20% by volume or less.
Even in the glass beads 64 containing Al, the content of Al in one glass bead is 5% by volume or more and 30% by volume with respect to the total volume of one glass bead for the same reason as that of the glass bead 63 containing Ag. The following is preferable. More preferably, it is 10% by volume or more and 20% by volume or less.

The light diffusing layer 4 includes a first light diffusing layer 4a and a second light diffusing layer 4b installed on the first light diffusing layer 4a, and includes a first light diffusing layer 4a and a second light diffusing layer 4b. May contain different types of glass beads 60. According to such a configuration, a difference in refractive index occurs at the interface between the first light diffusing layer 4a and the second light diffusing layer 4b, and the refractive index of the light diffusing layer 4 can be further improved.

The reflectance of the glass beads 60 contained in the second light diffusing layer 4b is preferably higher than the reflectance of the glass beads 60 contained in the first light diffusing layer 4a. According to such a configuration, the light diffusing action of the light diffusing layer 4 is further improved. That is, if the second light diffusing layer 4b and the first light diffusing layer 4a are arranged in the opposite direction, the light from the light emitting element 2 that has passed through the second light diffusing layer 4b will pass through the first light diffusing layer 4a. There is a risk. On the other hand, when the second light diffusing layer 4b is arranged on the first light diffusing layer 4a, the light from the light emitting element 2 transmitted through the first light diffusing layer 4a is reflected by the second light diffusing layer 4b. This is because the light diffusing action of the light diffusing layer 4 can be improved. Here, the reflectance of the glass beads 60 is higher in the order of the glass beads 63 containing Ag, the glass beads 64 containing Al, the glass beads 62 containing TiO ₂ , and the hollow glass beads 61. Therefore, for example, the light diffusion layer 4 may be a light diffusion layer 4 containing hollow glass beads 61 in the first light diffusion layer 4a and glass beads 63 containing Ag in the second light diffusion layer 4b.

Further, the first light diffusing layer 4a and the second light diffusing layer 4b contain different types of glass beads 60, and two or more different types of glass beads 60 are also contained in the first light diffusing layer 4a. And may contain two or more different types of glass beads 60 in the second light diffusing layer 4b. For example, the first light diffusing layer 4a contains hollow glass beads 61 and glass beads 62 containing TiO ₂ , and the second light diffusing layer 4b contains glass beads 63 containing Ag and glass beads 64 containing Al. The light diffusing layer 4 can be formed.

Further, the light diffusion layer 4 may have three or four layers, and each layer may contain different types of glass beads 60.
Further, the light diffusion layer 4 may have three or more layers, and at least one layer may contain glass beads 60 of a type different from the other layers. For example, the first light diffusing layer contains hollow glass beads 61, and the second light diffusing layer installed on the first light diffusing layer contains glass beads 62 containing TiO ₂ and is on the second light diffusing layer. The third light diffusing layer installed in may contain hollow glass beads 61.

The covering member 5 is a member that protects the light emitting element 2 and reflects light from the side surface of the light emitting element 2 to return the light to the light extraction surface side. The covering member 5 is on the side surface and / or the bottom surface of the light emitting element 2 and covers the light emitting element 2.
The material of the covering member 5 is a light-reflecting material having a reflectance of 60% or more, preferably 80% or more, and more preferably 90% or more with respect to the light emitted from the light emitting element 2. It is preferable to have. By providing the covering member 5, the light emitted from the light emitting element 2 can be efficiently taken into the light guide plate 6. Further, the covering member 5 also serves as a member for protecting the light emitting element 2 and a reflecting member provided on the surface opposite to the emission surface of the light guide plate 6, so that the light flux of the surface light emitting light source 100 can be improved. ..

The light-reflecting material of the covering member 5 is preferably a resin containing a white pigment or the like. Further, in order to reduce the cost of the surface light emitting light source 100, it is preferable to use an inexpensive silicone resin containing titanium oxide for the covering member 5.

The light guide plate 6 is a translucent member to which light from the light source 11 is incident and emits light in a planar manner. The light guide plate 6 may be formed with a first recess 6a for installing the light emitting element 2 at a position on the lower surface side facing the upper surface of the light diffusion layer 4. Here, the light guide plate 6 has a first recess 6a for accommodating the translucent member 3 and the light diffusion layer 4 on the second main surface opposite to the first main surface which is the light emitting surface.

The material of the light guide plate 6 includes a thermoplastic resin such as acrylic, polycarbonate, cyclic polyolefin, polyethylene terephthalate, and polyester, a resin material such as a thermosetting resin such as an epoxy resin and a silicone resin, and a translucent material such as glass. Can be used. In particular, the thermoplastic resin material is preferable because it can be efficiently produced by injection molding, and polycarbonate having high transparency and low cost is further preferable. In the surface light emitting light source 100 that forms the second wiring layer 17B after mounting the light emitting element 2 on the light guide plate 6, the step of high temperature such as solder reflow can be omitted, so that the surface light emitting light source is thermoplastic like polycarbonate and has heat resistance. Even low-grade materials can be used. Further, the light guide plate 6 can be molded by, for example, injection molding or transfer molding.

It is preferable that the light guide plate 6 has a flat upper surface side and a flat portion other than the first recess 6a on the lower surface side. That is, the light guide plate 6 is formed in a flat plate shape except for the first recess 6a. By having the light guide plate 6 having such a structure, the surface emitting light source 100 can be easily manufactured. However, a lens shape such as an unevenness or a Fresnel lens may be formed on the upper surface side and / or the lower surface side of the light guide plate 6. This is because the light toward the upper surface of the light guide plate 6 can be made uniform.

The light reflecting member 7A is a member that protects the light guide plate 6 and reflects light from the side surface of the light emitting element 2 to return the light to the light extraction surface side. The light reflecting member 7A is arranged around the covering member 5 to protect the light guide plate 6. The light reflecting member 7A is preferably made of the same light reflecting material as the covering member 5. Further, the covering member 5 and the light reflecting member 7A may be made of the same light reflecting material without partitioning.

In the light emitting structure 1, the light emitting element 2 and the translucent member 3 are bonded by a translucent adhesive member. The translucent adhesive member is preferably formed as a fillet on the side surface of the light emitting element 2. The light diffusion layer 4 may be formed by applying a light-transmitting material containing glass beads 60 onto the light-transmitting member 3. In the light emitting structure 1, the light guide plate 6, the translucent member 3, and the light diffusing layer 4 can be joined by a joining member. In this case, the translucent member 3 and the light diffusion layer 4 to which the light emitting element 2 is adhered are arranged in the first recess 6a formed on the surface of the light guide plate 6 on the light emitting element 2 side, and the wall surface of the first recess 6a is arranged. It is preferable to provide a joining member between the light-transmitting member 3 and the side surface of the light-diffusing layer 4. Further, a member forming the light diffusing layer 4 may be arranged in the first recess 6a of the light guide plate 6 and may be brought into contact with or adhered to the light emitting element 2 having the translucent member 3 to form the light diffusing layer 4. At this time, the light diffusion layer 4 having a predetermined thickness may be formed in advance. Further, the light guide plate 6 and the light reflecting member 7A can be joined by a joining member. As the translucent adhesive member and the bonding member, known adhesives such as epoxy resin and silicone resin can be used.

The light emitting module 10 includes a second wiring layer 17B that is electrically connected to the electrodes of the plurality of light emitting elements 2. In the light emitting module 10, the second wiring layer 17B is formed on the surface of the electrode of the light emitting element 2, the covering member 5, and the light reflecting member 7A. In the surface light emitting light source 100, the second wiring layer 17B and the conductive member 30 provided inside the via holes 18a1 and 18a2 are connected, and the light emitting element 2 of the plurality of light emitting structures 1 is electrically connected.

As described above, in the surface light emitting light source 100, the light diffusion layer 4 containing the glass beads 60 is installed on the light extraction surface side of the light emitting element 2. Therefore, the surface light emitting light source 100 can efficiently diffuse the light of the light emitting element 2. Further, since the light of the light emitting element 2 can be efficiently diffused, the shape of the light guide plate 6 can be made into a flat plate shape.

<Manufacturing method of surface light source>
Next, a manufacturing method for manufacturing the above-mentioned surface emitting light source 100 will be described with reference to FIGS. 7 to 8D.
FIG. 7 is a flowchart showing a method of manufacturing a surface emitting light source according to an embodiment. FIG. 8A is a cross-sectional view schematically showing a light guide plate prepared in the preparation step of the method for manufacturing a surface emitting light source according to an embodiment. FIG. 8B is a cross-sectional view schematically showing an intermediate prepared in the preparation step of the method for manufacturing a surface emitting light source according to an embodiment. FIG. 8C is a cross-sectional view schematically showing a state in which a light guide plate and an intermediate are bonded in the bonding step of the method for manufacturing a surface emitting light source according to an embodiment. FIG. 8D is a cross-sectional view schematically showing a state in which a wiring layer is formed in the wiring layer forming step of the method for manufacturing a surface emitting light source according to an embodiment.

In the method of manufacturing the surface light emitting light source 100, the light emitting element 2 in which the light guide plate 6 is prepared and the light diffusing layer 4 is installed on the light extraction surface side through the opening of the light reflecting member 7A installed in the base material 16. However, in the preparation step S11 for preparing the intermediate body 13 installed on the base material 16 with the surface opposite to the light extraction surface facing the base material 16, the light extraction surface of the light emitting element 2 faces the light guide plate 6. It includes a bonding step S12 for adhering the light guide plate 6 to the intermediate body 13 in a state of being moved, and a wiring layer forming step S13 for forming the first wiring layer 17A on the base material 16.
The light diffusion layer 4 contains glass beads, and the glass beads are one or more of hollow glass beads, glass beads containing TiO ₂ , glass beads containing Ag, and glass beads containing Al. Is. Hereinafter, each step will be described.
The materials and arrangement of each member are as described in the above description of the surface light emitting light source 100, and thus the description thereof will be omitted here as appropriate.

[Preparation process]
In the preparation step S11, the light guide plate 6 is prepared, and the light emitting element 2 having the light diffusion layer 4 installed on the light extraction surface side through the opening of the light reflection member 7A installed on the base material 16 takes out the light. This is a step of preparing an intermediate body 13 installed on the base material 16 with the surface opposite to the surface facing the base material 16.

In this preparation step S11, the light guide plate 6 having the first recess 6a formed is prepared. Further, in the preparation step S11, the light source 11 including the light emitting element 2, the translucent member 3, the light diffusing layer 4, and the covering member 5 is prepared. Then, the adhesive sheet 20 is provided on the base material 16, the second wiring layer 17B is provided on the adhesive sheet 20, and the light source 11 is arranged on the second wiring layer 17B. After that, the light reflecting member 7A is provided so as to cover the second wiring layer 17B. Alternatively, after the second wiring layer 17B is provided, a light reflecting member 7A is provided so as to cover the second wiring layer 17B, an opening is formed in the light reflecting member 7A, and a light source 11 is provided in the second wiring layer 17B through the opening. To place. In this way, the intermediate 13 including the base material 16, the adhesive sheet 20, the second wiring layer 17B, the light reflecting member 7A, and the light source 11 is prepared.

[Adhesion process]
The bonding step S12 is a step of adhering the light guide plate 6 to the intermediate 13 with the light extraction surface of the light emitting element 2 facing the light guide plate 6.
In this bonding step S12, the light source 11 is arranged in the first recess 6a of the light guide plate 6, and the wall surface of the first recess 6a and the side surface of the translucent member 3 and the light diffusion layer 4 are joined by a joining member. Alternatively, the light guide plate 6 and the light reflecting member 7A are joined by a joining member. As a result, the light emitting module 10 is formed on the base material 16 via the adhesive sheet 20.

[Wiring layer forming process]
The wiring layer forming step S13 is a step of forming the first wiring layer 17A on the base material 16.
In this wiring layer forming step S13, the first wiring layer 17A and the wiring pad 18 are formed on one surface side of the base material 16, and the covering layer 19 is formed with an opening for exposing the first wiring layer 17A and the wiring pad 18. Cover the material 16. As a result, the wiring board 15 is formed.
In this wiring layer forming step S13, a conductive portion that electrically conducts the plurality of light emitting modules 10 and the wiring board 15 is formed. At that time, in the wiring layer forming step S13, as the conductive portion, at least two via holes 18a1 and 18a2 formed for each pair of wiring pads 18, a conductive member 30 filled across the two via holes 18a1 and 18a2, and conductivity. A protective member 40 provided so as to cover the member 30 from one side is formed.

As described above, in the method for manufacturing the surface light emitting light source 100, the surface light emitting light source 100 in which the light diffusion layer 4 containing the glass beads is installed on the light extraction surface side of the light emitting element 2 can be manufactured. As a result, it is possible to manufacture a surface light emitting light source 100 capable of efficiently diffusing the light of the light emitting element 2.

<< Modification example >>
9 to 12 are cross-sectional views schematically showing a surface emitting light source according to a modified example. Here, the structure of the light guide plate is formed so as to be different from the surface light emitting light source 100 described above.
FIG. 9 is a cross-sectional view schematically showing a form in which a through hole is formed in a light guide plate. FIG. 10 is a cross-sectional view schematically showing a form in which a third recess is formed in a light guide plate. FIG. 11 is a cross-sectional view schematically showing a form in which a reflective film is provided on the lower surface of the light reflecting member. FIG. 12 is a cross-sectional view schematically showing a form in which a light transmitting member is used as a first member and a reflective film is provided at a position on the lower surface side of a light guide plate facing the upper surface of the light transmitting member.

In the surface light emitting light source 100A, the light guide plate 6A is formed with a through hole 6b for installing the light emitting element 2 at a position facing the light extraction surface of the light emitting element 2.
Specifically, the light guide plate 6A has a through hole 6b penetrating the first main surface and the second main surface, which can accommodate the translucent member 3 and the light diffusion layer 4. By having such a structure of the light guide plate 6A, it is not necessary to adjust the depth of the storage portion when the portion for accommodating the translucent member 3 and the light diffusion layer 4 is formed on the light guide plate. Therefore, the light guide plate can be easily manufactured, and the surface emitting light source can be easily manufactured. A reflective material such as a white resin may be provided in the hollow portion of the through hole 6b. The through hole 6b may be provided with a gap between the light source 11 and a reflective material such as a white resin or a translucent resin. However, the light guide plate 6A can accommodate not only the translucent member 3 and the light diffusing layer 4, but also a part of the light emitting element 2 and the covering member 5. This makes it possible to reduce the thickness of the surface emitting light source.

The surface light emitting light source 100A prepares the light guide plate 6A having the through hole 6b formed in the preparation step S11. The surface light emitting light source 100A can be manufactured by arranging the light source 11 provided with the light diffusion layer 4 arranged on the base material 16 via the adhesive sheet 20 and the second wiring layer 17B in the through hole 6b. Further, the surface light emitting light source 100A is a light source (light emitting element 2, translucent member 3 and covering member 5) having no light diffusion layer 4 arranged on the base material 16 via the adhesive sheet 20 and the second wiring layer 17B. ) May be arranged in the through hole 6b, and then the light diffusion layer 4 may be formed on the upper surface of the translucent member 3 through the through hole 6b.
Other matters are the same as those of the surface light emitting light source 100.

In the surface light emitting light source 100B, the light guide plate 6B is a surface opposite to the surface on which the first recess 6a is formed, and the second recess 6c is formed at a position where the first recess 6a overlaps when transmitted in a plan view. .. The light guide plate 6B is a flat plate having a flat surface. The second recess 6c is formed so as to reflect the light from the light emitting element 2 in a direction parallel to the plane of the light guide plate 6B.

The second recess 6c is provided to reflect the light from the light emitting element 2 and spread it in the direction parallel to the plane of the light guide plate 6B, that is, in the radial direction, and to average the light emission intensity in the plane of the light guide plate 6B. ing. The second recess 6c can be realized by various configurations such as providing a light guide plate 6B with a portion having a reflection or light diffusion function such as a lens. For example, it is possible to provide an interface with a substance having a refractive index different from that of the material of the light guide plate 6B such as air. Further, the second recess 6c is formed as a space of a recess of an inverted cone, and the size and shape thereof can be appropriately set. Specifically, it may be formed as a recessed space such as an inverted polygonal pyramid such as an inverted quadrangular pyramid or an inverted hexagonal pyramid. The second recess 6c is a recess formed in this way, and the light reflected at the interface between the light guide plate 6B, a substance having a different refractive index, and the inclined surface of the recess is emitted to the side of the light emitting element 2. That is, it can be configured to reflect in the radial direction with the second recess 6c as the center. For example, a light reflecting member or a light shielding member may be arranged in the second recess 6c. Further, the second recess 6c may be configured to be provided with a reflective film such as metal or a reflective material such as white resin in the recess having an inclined surface which is linear or curved in a cross-sectional view. The second recess 6c is preferably provided at a position where the optical axis of the light emitting element 2 passes through the center (the apex of the recess) of the second recess 6c.

Further, in the surface light emitting light source 100B, the light guide plate 6B has a third recess 6d formed on the lower surface side between the light emitting elements 2 adjacent to each other. The third recess 6d is formed so as to reflect the light from the light emitting element 2 toward the upper surface side of the light guide plate 6B. Since the surface light emitting light source 100B has the third recess 6d, the brightness of the light extracted from the first main surface of the light guide plate 6B can be improved.

The third recess 6d is formed as a space of a conical recess, and the size and shape thereof can be appropriately set. Specifically, it may be formed as a recessed space such as a polygonal pyramid such as a quadrangular pyramid or a hexagonal pyramid. The third recess 6d is a recess formed in this way, and the light reflected at the interface between the light guide plate 6B, a substance having a different refractive index, and the inclined surface of the recess is the first main component of the light guide plate 6B. It can be configured to reflect in the plane direction. Further, the third recess 6d may be configured to be provided with a reflective film such as metal or a reflective material such as white resin in the recess having an inclined surface which is linear or curved in a cross-sectional view.
The surface light emitting light source 100B can be manufactured by preparing the light guide plate 6B having the first recess 6a, the second recess 6c, and the third recess 6d formed in the preparation step S11.
Other matters are the same as those of the surface light emitting light source 100.

The surface light emitting light source 100C is provided with a reflective film 9 on the lower surface (second wiring layer 17B side) of the light reflecting member 7A. By providing the reflective film 9 on the lower surface of the light reflecting member 7A, the surface light emitting light source 100C can suppress the light from leaking downward through the light reflecting member 7A, and can improve the reflectance. Here, the reflective film 9 is provided on the lower surface of the light reflecting member 7A, the lower surface of the covering member 5, and the lower surface of the electrode of the light emitting element 2. That is, the reflective film 9 is provided on the upper surface of the second wiring layer 17B.
The surface light emitting light source 100C can be manufactured by preparing an intermediate in which the reflecting film 9 is provided on the lower surface of the light reflecting member 7A in the preparation step S11. The reflective film 9 can be formed by sputtering, electroless plating, or the like.

As the material used for the reflective film 9, for example, a simple substance metal such as Ag, Al, Ni, Rh, Au, Cu, Ti, Pt, Pd, Mo, Cr, W or an alloy containing these metals is preferably used. Can be done. More preferably, a simple substance metal such as Ag, Al, Pt, Rh or the like having excellent light reflectivity or an alloy containing these metals can be used. Among these, it is more preferable to use an Ag film using Ag having excellent light reflectivity.
Other matters are the same as those of the surface light emitting light source 100B. The configuration in which the reflective film 9 is provided on the lower surface of the light reflecting member 7A may be applied to the form of the surface emitting light source 100 and the surface emitting light source 100A.

The surface light emitting light source 100D is installed between the wiring board 15 having the second wiring layer 17B on the base material 16, the light guide plate 6B installed facing the wiring board 15, and the light guide plate 6B and the wiring board 15. Light extraction surface to the light guide plate 6B via the light transmitting member 7B, the reflective film 9 installed at the position on the lower surface side of the light guide plate 6B facing the upper surface of the light transmitting member 7B, and the opening of the light transmitting member 7B. It includes a light emitting element 2 installed on the wiring substrate 15 facing the side, and a light diffusion layer 4 installed on the light extraction surface side of the light emitting element 2. The light diffusion layer 4 contains glass beads, and the glass beads are one or more of hollow glass beads, glass beads containing TiO ₂ , glass beads containing Ag, and glass beads containing Al. .. Hereinafter, each configuration of the surface-emitting light source 100D will be described with respect to items that are mainly different from the surface-emitting light source 100C.

In the surface light emitting light source 100D, the reflective film 9 is installed at a position on the lower surface side of the light guide plate 6B facing the upper surface of the light transmitting member 7B. Specifically, the surface light emitting light source 100D is provided with a reflective film 9 on the inner surface of the third recess 6d and on the second main surface other than the first recess 6a and the third recess 6d in the light guide plate 6B. According to such a configuration, the surface light emitting light source 100D can reduce the ratio of the light transmitted through the second main surface of the light guide plate 6B, and can improve the reflectance.

Further, in the surface light emitting light source 100D, a light transmitting member 7B is installed between the light guide plate 6B and the wiring board 15. Specifically, the surface light emitting light source 100D is provided with a light transmitting member 7B on the second wiring layer 17B. The surface light emitting light source 100D can be configured to provide a light transmitting member 7B instead of the light reflecting member 7A as the first member 7 by providing the reflecting film 9 at the position on the lower surface side of the light guide plate 6B. As the material of the light transmitting member 7B, the same translucent material as the translucent material used for the translucent member 3 can be used. Further, the third recess 6d may be provided with a translucent material such as a transparent resin. It should be noted that the light reflecting member 7A may be provided without using the light transmitting member 7B. Further, the third recess 6d may be provided with a reflective material such as a white resin.

In the method of manufacturing the surface light emitting light source 100D, a light guide plate 6B having a reflective film 9 installed at a position on the lower surface side of the light guide plate 6B facing the upper surface of the light transmitting member 7B is prepared, and light transmission installed on a base material is prepared. The light emitting element 2 in which the light diffusion layer 4 is installed on the light extraction surface side is installed on the base material 16 with the surface opposite to the light extraction surface facing the base material 16 through the opening of the member 7B. The preparation step S11 for preparing the intermediate body, the bonding step S12 for adhering the light guide plate 6B to the intermediate body with the light extraction surface of the light emitting element 2 facing the light guide plate 6B, and the first wiring layer 17A on the base material 16. The wiring layer forming step S13 for forming the above is included.
The light diffusion layer 4 contains glass beads, and the glass beads are one or more of hollow glass beads, glass beads containing TiO ₂ , glass beads containing Ag, and glass beads containing Al. Is.

In the method of manufacturing the surface light emitting light source 100D, in the preparation step S11, the light guide plate 6B having the reflective film 9 installed at the position on the lower surface side of the light guide plate 6B facing the upper surface of the light transmitting member 7B is prepared. Further, in the preparation step S11, an intermediate in which the light transmitting member 7B is installed on the base material 16 instead of the light reflecting member 7A is prepared. Further, in the bonding step S12, the light guide plate 6B is bonded to the intermediate. Other matters are the same as the manufacturing method of the surface light emitting light source 100C.
The material and the forming method of the reflective film 9 are as described in the surface light emitting light source 100C.
In addition, the configuration in which the light transmitting member 7B is provided instead of the light reflecting member 7A and the reflecting film 9 is provided at the position on the lower surface side of the light guide plate facing the upper surface of the light transmitting member 7B is a surface emitting light source 100 and a surface emitting light source 100A. It may be applied to the form of.

Further, the method for manufacturing a surface emitting light source may include other steps during or before and after each of the steps as long as the steps are not adversely affected. For example, a foreign matter removing step of removing foreign matter mixed in during manufacturing may be included.
Further, in the method of manufacturing the surface emitting light source, the order of each step may be changed as much as possible. For example, the wiring layer forming step may be performed before the preparatory step, or the wiring layer forming step may be included in the preparatory step.

Further, as a method for manufacturing a surface light emitting light source, an intermediate in which an adhesive sheet, a second wiring layer, a light source and a first member are arranged on a base material is prepared, and then the intermediate and a light guide plate are bonded to each other. However, as a method for manufacturing a surface emitting light source, an intermediate in which a light source, a first member and a second wiring layer are arranged on a light guide plate may be prepared, and then the intermediate and the base material may be adhered via an adhesive sheet. ..
That is, in this case, in the preparation step, a plurality of light emitting modules and an adhesive substrate provided with an adhesive sheet on the base material for adhering the plurality of light emitting modules are prepared. The light emitting module can be formed by dicing a segment array in which a large number of light emitting structures are arranged as a light emitting module in which a predetermined number of light emitting structures are arranged with a dicing or the like. The adhesive sheet may be provided on the intermediate side, that is, on the light emitting module side.

Of course, in the surface emitting light source and the method for manufacturing a surface emitting light source described as the present disclosure, various changes can be made within the scope of the claims.

1 Light-emitting structure 2 Light-emitting element 3 Light-transmitting member 4 Light-diffusing layer 4a First light-diffusing layer 4b Second light-diffusing layer 5 Covering members 6, 6A, 6B Light guide plate 6a First recess 6b Through hole 6c Second recess 6d 3rd recess 7 1st member 7A Light reflecting member 7B Light transmitting member 9 Reflecting film 10 Light emitting module 11 Light source 13 Intermediate 15 Wiring board 16 Base material 17 Wiring layer 17A 1st wiring layer 17B 2nd wiring layer 18 Wiring pad 18a1, 18a2 Via hole 19 Coating layer 20 Adhesive sheet 30 Conductive member 40 Protective member 50 Glass outer shell 51 Air layer 52 TiO ₂
53 Ag
54 Al
60 Glass beads 61 Hollow glass beads 62 Glass beads containing TiO ₂ 63 Glass beads containing Ag Glass beads 100, 100A, 100B, 100B, 100C, 100D Surface emitting light source S11 Preparation step S12 Adhesion step S13 Wiring layer Formation process

Claims (23)

A wiring board having a wiring layer on the base material,
A light guide plate installed facing the wiring board and
A light reflecting member installed between the light guide plate and the wiring board, and
A light emitting element installed on the wiring board with the light extraction surface side facing the light guide plate through the opening of the light reflecting member.
A light diffusion layer installed on the light extraction surface side of the light emitting element is provided.
The light diffusion layer contains glass beads, and the glass beads are one or more of hollow glass beads, glass beads containing TiO ₂ , glass beads containing Ag, and glass beads containing Al. A surface emitting light source. A wiring board having a wiring layer on the base material,
A light guide plate installed facing the wiring board and
A light transmitting member installed between the light guide plate and the wiring board, and
A reflective film installed at a position on the lower surface side of the light guide plate facing the upper surface of the light transmitting member, and
A light emitting element installed on the wiring board with the light extraction surface side facing the light guide plate through the opening of the light transmitting member.
A light diffusion layer installed on the light extraction surface side of the light emitting element is provided.
The light diffusion layer contains glass beads, and the glass beads are one or more of hollow glass beads, glass beads containing TiO ₂ , glass beads containing Ag, and glass beads containing Al. A surface emitting light source. The surface light emitting light source according to claim 1, wherein a reflective film is provided on the lower surface of the light reflecting member. The surface emitting light source according to claim 2 or 3, wherein the reflective film is an Ag film. The light diffusing layer includes a first light diffusing layer and a second light diffusing layer installed on the first light diffusing layer.
The surface emitting light source according to any one of claims 1 to 4, wherein the first light diffusing layer and the second light diffusing layer contain the glass beads of different types from each other. The surface emitting light source according to claim 5, wherein the reflectance of the glass beads contained in the second light diffusing layer is higher than the reflectance of the glass beads contained in the first light diffusing layer. A translucent member is provided on the light extraction surface of the light emitting element, an upper surface of the translucent member is installed facing the light guide plate, and the light diffusion layer is provided on the upper surface of the translucent member. The surface light emitting light source according to any one of claims 1 to 6. The method according to any one of claims 1 to 7, wherein the light guide plate is formed with a first recess for installing the light emitting element at a position on the lower surface side facing the upper surface of the light diffusion layer. Surface emission light source. The light guide plate is a flat plate having a flat surface, and the light guide plate has a second recess formed at a position on the upper surface side facing the first recess, and the second recess receives light from the light emitting element. The surface emitting light source according to claim 8, which is formed so as to reflect in a direction parallel to the plane of the light guide plate. The surface light emitting according to any one of claims 1 to 7, wherein the light guide plate is formed with a through hole for installing the light emitting element at a position facing the light extraction surface of the light emitting element. light source. The light guide plate has a third recess formed on the lower surface side between adjacent light emitting elements, and the third recess is formed so as to reflect the light from the light emitting element to the upper surface side of the light emitting element. The surface light emitting light source according to any one of claims 1 to 10. The surface emitting light source according to claim 8, wherein the light guide plate has a flat upper surface side and a flat portion other than the first concave portion on the lower surface side. A light emitting element in which a light guide plate is prepared and a light diffusion layer is installed on the light extraction surface side through an opening of a light reflection member installed on the base material has a surface opposite to the light extraction surface as the base. A preparatory step for preparing an intermediate placed on the substrate facing the material, and
An bonding step of adhering the light guide plate to the intermediate with the light extraction surface of the light emitting element facing the light guide plate.
Including a wiring layer forming step of forming a wiring layer on the base material,
The light diffusion layer contains glass beads, and the glass beads are one or more of hollow glass beads, glass beads containing TiO ₂ , glass beads containing Ag, and glass beads containing Al. A method for manufacturing a surface emitting light source. The light guide plate having a reflective film installed at a position on the lower surface side of the light guide plate facing the upper surface of the light transmitting member is prepared, and the light extraction surface side is provided through the opening of the light transmitting member installed on the base material. A preparatory step in which a light emitting element having a light diffusing layer installed on the base material prepares an intermediate body installed on the base material with the surface opposite to the light extraction surface facing the base material.
An bonding step of adhering the light guide plate to the intermediate with the light extraction surface of the light emitting element facing the light guide plate.
Including a wiring layer forming step of forming a wiring layer on the base material,
The light diffusion layer contains glass beads, and the glass beads are one or more of hollow glass beads, glass beads containing TiO ₂ , glass beads containing Ag, and glass beads containing Al. A method for manufacturing a surface emitting light source. The method for manufacturing a surface-emitting light source according to claim 13, wherein the preparation step prepares an intermediate having a reflective film provided on the lower surface of the light-reflecting member. The method for manufacturing a surface-emitting light source according to claim 14 or 15, wherein the reflective film is an Ag film in the preparation step. In the preparatory step, the light diffusing layer includes a first light diffusing layer and a second light diffusing layer installed on the first light diffusing layer.
The method for manufacturing a surface-emitting light source according to any one of claims 13 to 16, wherein the first light diffusing layer and the second light diffusing layer contain the glass beads of different types from each other. The method for manufacturing a surface emitting light source according to claim 17, wherein the reflectance of the glass beads contained in the second light diffusing layer is higher than the reflectance of the glass beads contained in the first light diffusing layer. The preparatory step is any one of claims 13 to 18, wherein a translucent member is provided on the light extraction surface of the light emitting element, and an intermediate body provided with the light diffusion layer on the upper surface of the translucent member is prepared. The method for manufacturing a surface emitting light source according to item 1. The method according to any one of claims 13 to 19, wherein the light guide plate is formed with a first recess for installing the light emitting element at a position on the lower surface side facing the upper surface of the light diffusion layer. How to manufacture a surface-emitting light source. The method for manufacturing a surface emitting light source according to claim 20, wherein in the preparation step, the light guide plate has a flat upper surface side and a flat portion other than the first concave portion on the lower surface side. A wiring board having a wiring layer on the base material,
Light guide plate and
A first member that is partially opened and installed between the light guide plate and the wiring board,
A light emitting element installed on the wiring board through the opening of the first member, and
A light diffusion layer installed between the light emitting element and the light guide plate is provided.
The first member is a light reflecting member or a light transmitting member, and is a light transmitting member or a light transmitting member.
The light diffusion layer contains glass beads and
When transmitted in a plan view, there is a region where the light guide plate and the light diffusion layer overlap and a region where the light diffusion layer does not overlap.
A surface emitting light source in which the area of the light diffusing layer is the same as the area of the light emitting element or larger than the area of the light emitting element in a plan view. The surface emitting light source according to claim 22, wherein the glass beads are one or more of hollow glass beads, glass beads containing TiO ₂ , glass beads containing Ag, and glass beads containing Al.

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